Tech & Innovation in Healthcare

Strengthen Bone With Scaffolds

Researchers have discovered several ways to use 3D printing in healthcare. These uses include creating anatomic models for physicians to learn, crafting custom prosthetics and orthotics for their patients, developing medical instruments designed for specific procedures, and constructing custom implants.

One way healthcare professionals can use 3D printed custom implants is to create scaffolds to help bones heal that have been damaged due to trauma or surgery. The scaffold can stimulate bone regeneration and cell growth due to its porous design and a footprint that is tailored to precisely fit the patient’s bone.

With a variety of biological, synthetic polymer, natural polymer, and metal materials available, choosing the ideal substance to construct the scaffold is important. But which material stood out to researchers as a viable option for the bone scaffolds?

“Predominantly titanium alloy (Ti-6Al-4V) because of its good mechanical and corrosion properties. It has been researched extensively as an implantable material and has approval from bodies such as the U.S. Food and Drug Administration (FDA),” says Distinguished Professor Milan Brandt, director of the RMIT Centre for Additive Manufacturing at RMIT University in Melbourne, Australia.

The titanium alloy Brandt’s team explored falls under the monolithic metal category of materials. Most monolithic metals are stronger than a healthy bone, which can result in stress shielding around the implant over time. The stress shielding causes the bone density to reduce, since the implant is now absorbing the stress that the bone normally would absorb, and the implant can eventually loosen as a result.

However, advances in additive manufacturing have allowed researchers to develop implants that create an ideal stress balance between the implants and the patient’s bone. “Additive manufacturing has opened the possibility to tailor the properties of the implant through new designs such as lattice-based implants, which can have the same or similar mechanical properties to the removed bone. However, lattice-based implants cannot be manufactured conventionally,” Brandt adds. Due to their intricate designs, lattice-based implants are built through thermal additive manufacturing methods, such as LPBF.

Treating Lost Bone After Tumor Removal

“There is currently research going on globally on combining robotic surgery and 3D printed implants,” Brandt says.

For example, researchers in a collaboration between RMIT University, the University of Technology Sidney (UTS), University of Sydney, University of Melbourne, St. Vincent’s Hospital, and Stryker in Australia launched the Just-in-Time (JIT) Patient-Specific Tumour Implants project in 2017.

The aim of the project was to streamline “the development and delivery of implants to musculoskeletal [tumor] patients,” according to the Innovative Manufacturing Cooperative Research Centre (IMCRC) website.

By combining robotic surgery, advanced manufacturing, and 3D printing, healthcare teams can properly evaluate a patient’s condition and remove only what’s necessary to deliver precise treatment. “This allows minimal removal of healthy bone in case of bone cancers,” Brandt adds.

Check out previous issues of Tech & Innovation in Healthcare to learn additional uses of 3D printing in healthcare.